Method of making brake drums



March 29, 1938. A. s. VAN HALTEREN 2,112,697

METHOD OF MAKING BRAKE DRUMS Filed Jul 25, 1935 F/ a F/g 9 ATTORNEY.

Patented Mar. 29, 1938 PATENT OFFICE DIETHOD QF MAKING BRAKE DRUMS Andrew S. Van Halteren, Lansing, Mich, assignor to Motor Wheel Corporation, Lansing, Mich, a corporation or mchigan I Application July 25, 1935, Serial No. 33,081

4 Claim.

This invention relates to brake drums and the method of producing the same. Specifically, the invention relates to brake drums comprising a steel shell having an inner liner fused thereto and extending part way only into a hollow external rib at one edge of the shell whereby the outer portion of the rib may be flanged to form a seal and the provision of a method for producing such rings.

According, to the preferred embodiment of the invention two drums of the character mentioned are produced from a single strip of metal first formed to the desired shape to receive molten cast iron and then after the iron has been fused to the steel shell out to provide two identical brake rings-which may be attached to brake drum webs.

A The principal object of the invention is the provision of such a drum which has all of the o strength and wear resisting characteristics 01 the cast lined drums now in use but which is lighter, more economical to produce, and which may be deformed to provide an integral axially extending sealing flange at the open edge of the drum. The manner of attaining these and other objects will beapparent upon reading the following-description in connection with the accompa'nying drawing, wherein:

Figure 1 illustrates a flat strip of steel used in forming the shell for two drums;

Figure 2 shows the strip of Figure 1 coiled to cylindrical form;

Figure 3 shows the cylinder after the formation of a pair of external ribs intermediate its edges;

Figure 4 shows the cylinder afterlts edges have been turned inwardly to provide attaching flanges;

Figure 5 illustrates the manner in which the side walls of the external ribs are pressed together;

Figure 6 shows the cylinder after the opera- .tion illustrated in Figure 5;

v Figure '7 shows the cylinder after the cast liner has been fused thereto and indicates by dotted lines where the shell and liner are cut to produce a pair or cast lined rings;

Figure 8 shows the cast lined ring attached to a brake drum web, 'and assembled with its associated parts, the latter being shown in dotted lines; and

Figure 9 shows the cast lined ring and web assembled with a modified form of backing plate (dotted lines) the radial rib of the ring shell bent to form 1 In practicing the present invention a strip of sheet steel III, as shown in Figure 1, is selected of the desired length and width. It is then 5 coiled as indicated in Figure 2 to provide a cylindrical shell H. The ends of the strip are welded together as indicated at l2 in Figure 2.

The cylinder II is next submitted to-conventional rolling operations whereby the two ex- 10 ternal ribs l3 are formed intermediate the edges of the shell (see Figure 3). The ribs I! are quite close to each other and extend completely around the shell ll.

an axially extending seal The cylinder II is next operated upon to pro-. 15.

vide the inturned flanges I I at its opposite'edges. This operation may be performed by any conventional method. The flanges serve as side boards to retain the molten cast iron which is subsequently introduced into the shell and also as attaching flanges in the finished brake It is desired to prevent the molten cast iron from filling the ribs l3, as has been the practice heretofore in order to minimize the quantity of 25 iron required and also to permit the bending of the ribs to form seal flanges. To thistend, the cylinder is next treated as illustrated in Figure 5 to close the outer portion of the ribs. As there shown the cylinder is mounted on a platform 3 IS with an annular spacer l6 between the ribs ii. A movable die i1 is arranged to press against the outer wall of the adjacent rib IS. The platform I5 is hollow to receive the cylindrical portion of the shell H. The die I! is likewise hol- 35 low for a similar purpose. The spacer I6 is preferably made up of two or more sections which are inserted between the ribs l3 beiore the shell H is mounted on platform IS. The radially outer surface of spacer I 6 is inclined to 40 contact the inclined side wall I! of platform 15 whereby the metal between ribs I3 is pressed inwardly during the closing of the ribs. Platform into it, the molten iron flows into the base only.

of the ribs l3. Figure 'I shows the shell afterthe cast iron has been introduced as just deflange 26 cooperating with rib l3 to efl'ect a seal scribed. The cast liner is indicated at l9. During the introduction and solidifying of. the cast iron the flanges ll serve to hold the molten metal in the rotating shell. taching a cast liner in this manner is now in use and is well known.

After the cast iron liner I! has been fused to the shell H and has solidified, an annular section of the shell and liner located between the ribs I3 is removed by cutting the same along dotted lines 20 (Figure 7). In this manner two identical cast lined brake rings are produced, each having an attaching flange ll at' one edge and an external rib I3 at the other edge. To prepare the ring thus formed they are next machined to proper size as shown by the dotted lines 2| in Figure 7. They may also be sized by a conventional, sizing operation, if desired.

After the machining and sizing operations the cast lined rings are ready for assembly in a brake drum. As shown in Figure 8 the cast lined ring is attached to a brake drum web 22 by rivets 23. dotted lines. A backing plate 25 also shown in dotted lines is mounted adjacent the open side of the drum inthe usual manner. The backing plate 25 is here shown as having a peripheral for the brake drum to prevent the entrance of foreign matter into the drum.

Figure 9 illustrates a modified arrangement of the drum assembly. In this instance, the ring is also attached to a web 22, but the radial outer portion of the rib I3 is bent axially to form a seal flange 21. This is made possible only by reason of the fact that the cast liner does not extend into this outer portion of the rib. In this form of arrangement the backing plate 25 is preferably provided with seal rings 28 and 29 in addition to the peripheral flange 28. In this manner a more efiective seal is formed.

From the foregoing-description it will be apparent that this invention not only provides an improved form of cast lined brake drum but also a novel and economical method of producing the same. Obviously the form of the drum and the manner of utilizing the process may be varied within wide limits without departure from the spirit or scope of the invention as deflned by the appended claims. e

The method of at- The web is mounted upon a hub 24 shown in' I claim:

1. The method of producing brake drums which comprises providing a sheet metal cylinder, forming an annular external stiflening rib in the cylinder, centrifugally casting a metal liner to the cylinder with a portion thereof extending into said annular rib, thereafter bending the rib to form an axially extending sealing element, and attaching a brake drum web to one edge of the cylinder.

2. The method of producing brake drums which comprises providing a metal cylinder, forming a pair of external annular reinforcing ribs intermediate the edges of the cylinder, centrifugally casting a metal liner within the cylinder with a portion thereof extending into said annular ribs, severing the cylinder intermediate the ribs along a circumferential line to form a pair of identical brake rings each having an annular rib at one edge thereof, bending the ribs at the edge of each of the rings to form an axially extending sealing element, and attaching a brake drum web to each of the rings at the edge opposite from the sealing element.

3. The method of producing brake drums which comprises providing a metal cylinder, forming a pair of hollow external reinforcing ribs intermediate the edges of the cylinder, pressing the two sides of each of the ribs together in a manner to form an annular groove at the base of each of the ribs, centrifugally casting a metal liner within the cylinder with a portion thereof extending into each of said grooves, severing the cylinder intermediate the ribs along a .circumferential line to form a pair of identical brake rings each having an annular reinforcing rib adjacent one edge thereof, and attaching a brake drum web to each of the rings at the edge remote from the reinforcing rib.

4. In the manufacture of brake drums, the method which includes the steps of providing a metal cylinder, forming a pair of hollow external reinforcing ribs intermediate the edges of the cylinder, pressing the two sides of each of the ribs together in a manner to form an annular groove at the base of each of the ribs, and thereafter severing the cylinder intermediate the ribs along a circumferential line to form a pair 01. identical brake rings each having an annular reinforcing rib at one edge thereof.

ANDREW S. VAN HALTEREN. 

